running to RB-1080s, strange behavior on one...

[ou8thisSN]

In the theater room I have 2 RB-1080s. I'm using the two of them to power the front stage: 2 Klipsch RF-7s and 1 RC-7.

So I have 1 amplifier powering only the RC-7, and the other powering both the right and left RF-7s.

The issue is that while everything SOUNDS fine, there could be an issue, which I'm wondering about:

When I turn the system off, the red "protection" light ONLY turns on the RB-1080 thats powering the center channel. It does NOT turn on for the RB-1080 that is powering each of the two RF-7s.

There's also a characteristic high pitched squeal that comes from the center channel after about 30 seconds when the system has been turned off, ie the capacitors being discharged.

Again, this sound ONLY comes from the RB-1080 that powers only the center channel, not from the one powering the RF7s.


In another system, I have another RB-1080 powering two RF83s. On this system, the RB-1080 works just like the one powering the center channel. Same protection red light that comes on after the system is shut off, and the same characteristic squeal after the system is powered down.

So is this an amp issue or nothing I should worry about. Again, everything sounds fine, but its the same amp, why wouldnt they all act the same way?

[Ken49r]

How do you power up and down your system? In what order is amp?

[ou8thisSN]

It's daisy chained through a Denon 3803, 12-v trigger. The Denon 3803 turns on first, then the trigger essentially turns on both RB-1080's simultaneously. There's only one 12v trigger out on the Denon, so it turns on the center channel rb-1080, and then the 12v trigger from that rb-1080 turns on the second rb-1080 that powers the front left and right speakers.

[ou8thisSN]

i just did an experiment. I took the 'odd functioning' rb-1080 out of the theater room, and moved it downstairs where it is now powering the RF-83s. I ran the system for about 20 minutes at a high enough volume to break in the amps, and the same thing happens, the protection light doesnt come on when the system is turned off, nor do the sound of the capacitors discharging come out of the speakers.

Is this just a new design I'm not aware of, or a serious problem in the making?

[joetama]

Sounds like the protection circuit of the one RB-1080 isn't kicking on. When you turn the power off the light for protection should turn on, if it doesn't there is something wrong with that section of the amplifier.

How old are the amps?

[ou8thisSN]

I bought two RB-1080s in september of 2008 (i have had another RB-1080 for about two years now), so these 'new' ones are less than 4 months old. I think there's a serious problem, because not only doesnt the protection light come on, but when I go into the system setup (i'm running this with a RSP-1068), and turn OFF the subwoofer, and send all the bass information to the RF83s, I cant tell any difference in sound quality between setting the speakers as SMALL w/o sub and LARGE.

The RF83s are plenty capable of putting out a good amount of bass without needing a subwoofer and I'm very familiar of what it should sound like without the sub. With the 'new' RB-1080 from the upstairs now running both the RF83s downstairs, in the LARGE setting, I'm not getting any bass.

If I contact rotel, will they likely repair the amp or allow my dealer to swap it out for a new one? any idea of what they are like with customer service?

[joetama]

I've always heard mixed things about Rotel service, but I believe in general they are very on top of things. The swap out will probably be up to your dealer. I know some will do that and others wont.

But, I would definitely get it looked at before something catastrophically bad happens.

[ou8thisSN]

I've always heard mixed things about Rotel service, but I believe in general they are very on top of things. The swap out will probably be up to your dealer. I know some will do that and others wont.

But, I would definitely get it looked at before something catastrophically bad happens.

I've noticed this from the first day, but I was too lazy or didnt pay enough attention to think this was a big deal, till today. I'll find out from my dealer what my options are. When I was buying these amplifiers, I was told that Rotel was changing out their stock for the RB series, so I got the dealer's last two of this. So, I'm not optimistic about a swap out, but it doesn't hurt to ask.

[joetama]

I've noticed this from the first day, but I was too lazy or didnt pay enough attention to think this was a big deal, till today. I'll find out from my dealer what my options are. When I was buying these amplifiers, I was told that Rotel was changing out their stock for the RB series, so I got the dealer's last two of this. So, I'm not optimistic about a swap out, but it doesn't hurt to ask.

If it has been doing it since day one then there probably isn't too serious of a threat of something else happening. I would still get it fixed however. Maybe you can talk him into a deal for something from the 15 series stuff. You never know is often true. Especially with Hi-Fi dealers, ask them something on a Tuesday get one answer. Ask them on a Thursday get a completely different answer.

[ou8thisSN]

If it has been doing it since day one then there probably isn't too serious of a threat of something else happening. I would still get it fixed however. Maybe you can talk him into a deal for something from the 15 series stuff. You never know is often true. Especially with Hi-Fi dealers, ask them something on a Tuesday get one answer. Ask them on a Thursday get a completely different answer.

I dont like or want the new stuff. As far as I can tell, all the new amplifiers are class-D tech. I also really enjoy the symmetry of my 2 rb-1080s. this discussion is moot till i talk to my dealer, but i'll update the thread. thanks for reading!

[ou8thisSN]

i went into my dealer, they said they have to do a swap out with Rotel, so I have to take it in... if thats my only choice, lets see what happens. I am kicking myself for not having dealt with this back in october.

[ou8thisSN]

update: as I feared, I sent it into Rotel and it was there for about 5 weeks. It came back with a clean bill of health. They said they tested it extensively, and resoldered all the connections and found nothing wrong. As soon as I plugged it in, it was behaving just like it used to.

I'm thinking about taking a video of what's happening, comparing the two amps simultaneously and sending that into rotel to look at. I really fear that I got a lemon and am not being taken seriously, and I dont know how/if they will believe me. Suggestions?

[joetama]

Bummer man sorry to hear this... If you take the videos post them here too.

[copycat]

Feel you pain

Picked up one of the last RB1090's. Worked flawlessly for a year and had the fault lights come on and stay on. Returned it to dealer, and they in turn sent it back to Rotel. 5 weeks later got the call that everything was taken care of. I had two bad grounding transisters. Heard that there are only a couple of guys servicing the gear in Mass. and that there bench is loaded. Just one of those things I suppose.

[ou8thisSN]

yep same. I picked up the last two pair of RB1080s at the dealer. One works great, the other one has this issue where I can clearly tell it's acting up, but Rotel wont believe it, and insists its fine. I resent that I have to go through this much effort to prove my case to them...

[copycat]

Just returned with my serviced 1090. 5 weeks in Mass. Will return the Ampzilla to the closet. Talked to the tech at the audio shop about the new D class amps. In his opinion their not as musical. Have plenty of power put lack the sound quality of the A/B gear. I bet their the same sounding as my old Carver M500's.